Recapping and retreading mold



Sept 18, 1951 H. L. BAKER E-.rAL l 2,567,985

l REC'APPING AND RETREADING MOLD I Filed March 50, 1946 5 Sheets-Sheet 1 INVENToRs #Amm L. Mm? ldY/WCWD 0. VIA/'WELL v Wy, mf@

Sept. 18, 1951 lH. L. BAKER ETAL 2,567,985

-` RECAPPING AND RETREADING MOLD Filed March 30, 1946 5 Sheets-Sheet 2 l INVENTOR.:

f HARaLD L. BAKER y' By KAYWA/p a uw 7mm Sept. 18, 1951 .l H. L. BAKER ETAL 2,567,985

RECAPPING AND RETREADING vMOLD Filed March 30, 1946 5 Sheets-Sheet 5 Y INVENTORS HAROLD L. BAKER BYRAYMA/D D- V/V TSGELL Sept. 18, 1951 H. LfBAK-ER ET AL RECAPPING AND RETREADING MOLD 5 Sheets-Sheet 4 Filed March 3o, 1946 Sept. 18, 1951 H. l.. BAKER ET AL RECAPPING AND RETREADING MOLD 5 Sheets-Sheet 5 Filed March 50, 1946 Patented Sept. 18, 1951 UNITED STATES PATENT RECAPPIN G AND RETREADIN G MOLD Harold L. Baker, Fresno, and Raymond D.

Van Tassell, Danville, Calif."

Application March 30, 1946, Serial No. 658,522

(Cl. 1s-1s) f Claims.

more conveniently, efficiently, and faster than heretofore.

Another object of the invention is the provision of a retreading mold in which the annular matrix is divided into a plurality of segments that are adapted to move simultaneously and bodily directly radially outwardly of the central axis of the matrix from a closed or curing position, and vice versa, and which mold includes heating means automatically positioned in heat transfer relation to said matrix when said segments are in curing position.

A still further object of the invention is the provision of means in a retreading mold for quickly releasing a tire casing from the matrix or matrices Without injury to the tread or casing in the event the tire casing should become stuck to one or more of the matrices.

Other objects and advantages will appear in the description and in the drawings.

In the drawings, Fig. 1 is a top plan view showing the segments of the matrix in open'position.

Fig. 2 is a vertical sectional view through the mold when the segments of the matrix are in open position, which view is taken along line 2-2 of Fig. 1.

Fig. 3 is a top plan view of the mold showing the segments of the matrix in curing position.

Fig. 4 is a sectional View taken along the line 4 4 of Fig. 3.

Fig. 5 is an enlarged fragmentary sectionalview of a portion of the mold. showing a tire casing in the mold and the means for releasing the tire cas- Ashowing a modied form of the moldwhen the segments thereof are in expanded or open tion.

Fig. 9 is a vertical sectional view through the mold of Fig. 8.

Fig. l0 is a top plan view of the mold of Fig. 8 in closed or curing position.

Fig. 11 is a vertical sectional view of the mold of Fig. 10.

posi- 2 Fig. 12 is an enlarged fragmentary sectional view taken through one of the airinlets in one of the segments of the lmatrix for admitting air under pressure to blow the tire casing loose from a segment to which it may become stuck.

In detail,`the' mold illustrated in Figs. 1 to 'i comprises a frame that includes legs I connected by base members 2, which base members may carry a vertically disposed hydraulic cylinder equally spaced from said legs.

Supported on the upper ends of legs I is an annular hollow member 4 that provides a steam chamber having a partition 6 at one point therein, and a steam inlet I and an outlet 8 at opposite sides of vsaid partition, which inlet and outlet are suitably'valved in the conventional manner for controlling the admission and discharge of steam to within said chamber.

'I'he radially inwardly facing wall 9 of said steam chamber tapers upwardly and outwardly transversely of the chamber, as best seen in Figs. 2, 4.

A piston rod I0 extends vertically upwardly through the head of cylinder 3, said rod being connected at its lower end with a-conventional piston (not shown) that is reciprocable in cylinder 3. Any suitable valved fluid pressure line I I connects with the lower end of the cylinder 3 for admitting fluid under pressure into the cylinder below the piston and for .discharge of fluid from said cylinder for causing the rod to reciprocate vertically.

The upper end of rod Ill is secured to a table I3 rthat is formed with four equally spaced slots I4 4extending radially of the axis of rod I0, and which slots are equally spaced from said rod.

Slidablysupported on table I3 are four equal sections I5 of a circular matrix plate, each of which sections is positioned over a slot I4, and

guideA strips I 6 are respectively secured by cap screws I'I to each section I5 ofthe matrix plate, which strips extend into slots I 4 ,for sliding therein longitudinally of the latter.

A A depending ear I8 is on each strip I6, and links I9 are respectively p ivoted at one of their ends to said ears, the opposite ends of said links being pivotally secured to each of the four legs I. Each link I9 spreferably in two pieces, which pieces are connected byA a turnbuckle connector 20 for adjusting the length o f each link. Also adjustable stops 2I are provided at the ends of slots I4 for providing bumpers adapted to be simultaneously engaged by the strips I6 at the ends of their outward movement in said slots.

Secured along the peripheral outer" edge of each section I 5`is a segment 22 of thematrix, said matrix being annular and divided vequally to form four equal segments 22. These segments are in end to end relation to form the annular matrix when tli''segments are in closed orxcuring position as seen in Figs. 3, 4.

Each segment 22 is releasably secured'to one of the sections l5 by astud andllatch structure', as best-seen in Figs. `v6, 7, in which Va plurality of spaced stud bolts 24 are secured to the underside of each segment 22. These studs are each formed with an enlarged portion 25 (Fig. 7) .that extends through an opening in the margin ofthe section l5 and which enlargement also provide a stop shoulder abutting the section.

A. restricted neck portion 26 is between .the head 21 of the stud bolt andthe enlargement'25. This neck portion 26 is adapted to be received between the sides of a slot 28 (Fig. 6) that opens inwardly of one .side of the outer end of a latch bar 29. There is alatch bar 29.fo r each stud-bolt, and each latch Lbar lis -pivotally `secured to @the section l5 .at the vinnerrend of each barffor .swinging of the-outerrend to and from a-position vengaging the .stud bolts. Whenthe latch bars are swung tov positionsfout of v.engagement .with .the stud bolts the segments 22 ymay be lifted .from the sections l5 for replacement by .other .segments for accommodating different sized tire casings.

The .outer vperipheral sides y30 `(Fig. '-2) of the matrixsegments are inclined .to correspond with the inclination of .the inners'ides-dof the .steam chamber 4, and when the .segments 22 are `in closedfcuring position, the .saidasides -.30, I9 `are in .close heat `transfer engagementwith each other and the links I9 are substantially horizontal, -as seen -in Fig. 4.

.In operation, iiuid pressure .-is admitted through pressure line 'H .into .the flower Vend of cylinder 3, thus moving the piston rod I0 up- .wardly and elevating the sections i5, .including the segments .22 carried thereby. Since Ylinks IS `aresecuredtothe .legs v.l at one of :their ends,the

4 VVbar .hasia collar 33 thatzisiadapted to .receive an `-.upwar.l extension4 39 of .thepiston .rod il). Thus the tire will be held against being pulled to one side by the segment in which it is stuck and upward movement -of Ythe .sections .I9 will vresult Y radially inwardly `to .the 4closed or .curing vposi- Y tion andat .the same time-.thesides 3U of thematrix segments will move .into fheat .transfer engagement with the .sides 9 4of the fsteamchamber.

There is the .conventional bag 32 within the tire-casing-33 (Eig. 5) .when the .segments 22are in .closed position to .produce -the requisite internal pressure, said bag 'being .held in the casing by the usual collapsible `rim 34.

The retreading ,or recapping rubber on .the casingis cured `by the ,heat .from the .steam chamber and the pressure from the Iair bag, after which the sections '1.5 are again .elevated byadmission of iiuid under @pressure into the lower end of the vcylinder 3, .it be'ing understood "that the upper line 3l is open vtodischarge or .to the inlet side of a pump where such pump may be used to create the desired pressure.

In the event that the casing 33 should be stuck in any one of the segments, a bar '35 is connected `t0 the rim 34 at the side where the sticking occurs, or at the Opposite side, which rim is provided with an eye 36 for an angular extension 3E at one end of said bar. The opposite end of vthe the tire will be pulled loose from the segment as `the segments continue their movement to open position. The bag 32 does not normally stick 'to the casing, and under any circumstance its degree of adhesion is negligible. The degree of radial movement of each segment 22 is substantially greater than the maximum degree to which the bag 32 can abe flattened at any one side, .andas the conventional .casing is incapable of stretching circumferentially no diicu'lty is experienced in releasing the casing `from any of the segments.

When .the .segments are in open position the casing .may .readily be lifted .from .the .sections I5 on which it is supported, and a new tire may be .quickly placed on .said sections for repeating the operation.

The mold of YFigsf to 1'2 is lpractically the same as that described above, except that the steam .chamber moves downwardly away 'from the matrix, instead of vthe matrix moving upwardly .away `from. the steam chamber.

There .are .other features 'in the mold ofFigs. 8 to 1'2 that may be used with the mold of Figs. l to tnwithout difliculty,an'd .these ."fea'tures will be described 'in due-course.

The mold of Figs. 8 'to 'l2 comprises vertical vlegs 4D and .a base member '4| securing their .lower ends in .spaced relation. A vertical `hy draulic cylinder 43 is on said'base equally spaced from said legs. "Said cylinder contains a vertically reciprocable piston .therein (nots'hown') and a `piston rod A'44 .secured Iat one Iend to said piston extends through -the cylinder head.

The upper end of the .piston rod 4'4 is secured to a horizontal -plate '45 centrally of the latter, said plate carrying .an :annular hollow member 4B spaced above its marginal .portion -by legs 41. Thus member 46 provides a steam chamber 'that is identical with the member f4 o'f`Figs`1, '2,'having -an inner upwardly and. outwardly inclined side .wall 48. Y

Secured on the upper .ends of legs 4'0 is a radially slotted table 549, said slots lbeing indicated at 50 (Figsf9). Equal sized sectionsl of a circular matrix plate are supported over said table and' each section has .a .guide strip 52 extending through the slot`5 therebelow Ears "54 'depend below said guide strips and are secured toi-said strips. There are four sections 5| in'themold of Figs. 8 .to ll, the same 'as in the .previously described mold, yand there .are `also -four l'legs 40.

A'link 55 Ais .pivotall-y secured at one end to each ear 54, and the opposite end of each link is ,pivotally secured to each leg 4'! that 'is rigid with the steam chamber.

Secured on -the matrix sections 5I are matrices or segments 58 'of the annular matrix. These .segments have .outer Ainclined lside Walls 59 that correspond in inclination `to the inclined walls 48 of thesteam chamber. n

The segments '58 form a continuous annular matrix vwhen rthey `are in end to .end .adjoining relation as seen in Figs. 10, 1l, and which position .may be ter-med the curing or closed position. When said segments are 4-in :the curing position the linksam-horizontal and ythe matrix is circumferentially enclosed .by the steam chamber in heat transfer .relation with -said chamber. Also fluid under pressure Vhas b'een admitted into the lower end of cylinder 43 through line 60 causing the piston rod and the steam chamber to be in elevated position.

Upon releasing the fluid' pressure below the piston-in cylinder' 43 the plate 45 and the steam chamber will be lowered, whereupon the links 55 will automaticallypull the sections 5l and the matrix segments 58' to open position as seen in Figs'. 8, 9 for removal of a vulcanized tire and insertion 'of another casing to be recapped or retreaded.'v

Adjustable stops BI may be carried by the plate 45 for abutting the underside of the table '49 thus limiting the upward movement of the steam chamber.

j The steam chamber itself has a partition 63 (Fig. 9) at a point therein, and a valved steam inlet 64 and outlet 65 are respectively at opposite sides of said partition.' n

Each segment 58 is hollow and vformed with a plurality of spaced ribs 66,- several of which may be formed with through passageways 6'! (Fig. 12) that open at one of their ends outwardly of the outer peripheral surface of the segments, while the inner or opposite ends of said passageways open into the tread portion of each segment.

The inner ends of passageways 61 where they open into the tread portion of each segment are ared outwardly'and a tapered valve memb'er 68 of the tappet type is seated in eachflared end closing the passageway -to ow of rubber into the passageway( Each member 68 has a stem 69 around which is an expansion coil spring 10 reacting between a collar 'H and a shoulder inv each passageway for yieldably holding the valve member 68 closed.

The outer end of each passageway 61 threaded to receive a standard tting. on the end of a compressed air line. In the event a casing should become stuck to vany segment 58, the tread may readily be blown loose from the segment without injury to the casing by aflixing a compressed air hose in the proper passageway 61.

In this form of the invention the tread portion of each matrix segment may be provided with a removable tread plate 15 that may be slid longitudinally out ofthe segment after removal of the valves for replacement by other tread plates of different design.

It is obvious that the same or similar provision for releasing tires from the matrix segments by blowing them loose may be used in the form of the invention shown in Figs. 1 to 7, and also the means employed in Figs. l to 7 for mechanically releasing a stuck tire may be used in the form of mold shown in Figs. 8 to l2: Where the valves 68 are not used, the removal of tread plates 15 is greatly simplified.

The structure for securing said tread' plates in position includes opposedly opening grooves 'I6 formed in the sides of the segments 58 as seen in Figs. 9, 11 and 12.

It is to be understood that the detailed description and drawings are not to be considered restrictive of the invention, but merely illustrative thereof.

We claim:

l. A retreading mold comprising a matrix providing an `annular tread curing surface, said matrix being divided into a plurality of segments, means supporting said segments for bodily movement radially of the axis of said matrix and free from pivotal movement from curing position with said segments in end to end adjoining relation to open position in which said segments are spaced from each other in a common plane, heating means for said matrix in heat exchange relation thereto when said matrix is in said curing position, said matrix and said heating means being relatively movable to spaced'relation for, rendering" said heating means inoperative for supplying heat to said matrix, and means for causing said relative movement of said 4,matrix and said heating'means, the upwardly projected area over said matrix being free at alll times from obstruction to insertion of a tire casing' into said matrix and to removal of a tirer casing therefrom.

2. A retreading mold comprising a matrix providing an annular tread curing surface, said matrix being divided into a plurality of segments, means supporting said segments for bodily movement radially of the axis 'of said matrix and free from pivotal movement from curing position with said segments in end to'end adjoining relation to open position in which said segments are spaced from each other in a common plane, a hollow annular member for cirv r cumferentially enclosing said matrix when thev latter is' in said curing position in heat transfer relationship with said matrix providing a steam' chamber for supplying heat to said matrix, means supporting said member and said matrix' for axial movement relative to each other to spaced relation during all of said movement of said segments radially of said axis whereby said matrix and said memberwill be moved simultaneously axiallyv and radially out of heat transfer relationship with each other when said matrix is moved to open position.

3. A retreading mold comprising an annular matrix divided into a plurality of segments, means supporting said segments for bodily movement radially of the axis of said matrix'and free from pivotal movement 'from a curing position with said segments in end to end adjoining relation to open 'position with said segments spaced apart in a common plane, means supporting said segments for movement axially of said axis, means for simultaneously so moving said segments axially and radially, and a heater positioned for heating said segments when the latter is in said curing position only.

4. A retreading mold comprising anannular matrix divided into a plurality of segments,` means supporting said segments for movement radially of the axis of said matrix from a curing position with said segments in end'to end adjoining relation to open position with said segments spaced apart in a common plane, an annular heater in heat transfer relation with the outer periphery of said matrix when the latter is in said curing position, means forrelatively moving said heater and said matrix axially of said axis for urging said segments to said open position, said matrix being adapted to circumferentially enclose a tire casing when in said curing position with said casing l coaxial therewith, 'and means for holding such casing from movement radially of said axis upon movement of said segments to said open position.`

5. A retreading mold comprising an annular matrix divided into a plurality of segments, means supporting said segments for bodily movement radially of the axis of said matrix and free from pivotal movement from a curing position with said segments in end to end adjoining relation to open position with said segments spaced apart in a common plane; an annular heater `for circumferentially enclosingsaid matrix in heat transfer Krelation thereto when said matrix is in said curing position, and said rst mentioned 'means including `a table movable vaxially with said segments for supporting a tire casing'c'oaxial with said -matrix and in said common -plane when said matrix is in said open position.

`l6. A retreading mold comprising Aan annular generally horizontally positioned matrix divided into a plurality of segments, said segments being movable bodily radially of the axis of said matrix and -free from pivotal movement from a curing position with their ends in adjoining Fend to end relation to an open position `with said segments spaced vapart in a common plane, 'means supporting said segments for said movement, means for simultaneously so moving said vsegments., and means ffor heating said segments equally when 'they are in Asaid curing position, said means supporting said segments including a table "movable with vsaid segments below said matrix and movable axially with said segments forsupporting a tire casing within the confines of said :matrix and in said common plane.

v7'. A retreading mold -comprising an annular generally horizontally positioned matrix divided into .a plurality of segments, said segments being movable `bodily radially Yof the axis of said matrix and free -from pivotal movement from a curing .position with their ends in adjoining end to end relation to an open position with said segments spaced apart in .a common plane, means supporting ysaid segments for said movement, means 'for ysimultaneously so moving said segments, the outer peripheral surfaces of said segments 'being tapered outwardly transversely thereof in an upward direction, an annular heater circumferentially enclosing said segments when the `latter are in said curing position, said heater .having Aa radially inwardly facing surface tapered `to correspond with the tapered 'peripheral surfaces Aof said .segments Vand in close heat transfer Arelation with the ysaid peripheral surfaces when 'said segments are in `said closed position, :and means for moving said segments and said heater relatively axially of 4the axis 'offsaid heater upon said movement of saidsegments radially, `said yrelative movement being in a direction for spacing lsaid matrix at a level above that of said heater.

8. A retreading mold comprising an -annular generally horizontally positioned matrix divided -into la plurality :of segments, -a platform slidably supporting `said segments for bodily movement radially of the axis of said `matrix from a curing position in which the ends of said `segments :are in .end to end adjoining relation to an open position in which said segments are spaced apart in a lvcommon plane, an `annular heater circumerentially enclosing said matrix in heat transfer relation thereto when said segments are in 'said :curing position, a plurality of links respectively pivotally connected at 'their ends with 'said heater and with .said respective segments, said links extending radially of the axis of said matrix 'when said segments yare .in said closed position enclosed by said heater, and means for moving ysaid heater .and said matrix axially relative .to .each other Vwhereby the ends of the links 'connected with .said segments will be caused to swing radially outwardly of said axis for moving `saidsegments to said open position.

`9. :1A yretreading mold .comprising an annular generally horizontally Ypositioned vmatrix divided into a :plurality of segments, a ,platform .slidably supporting said segments for -bodily -movement radially vof the axis of .said matrix from a Vcuring position in which the ends of said segments .are in end to end 4adjoining relation to an open position inwhich :said l.segments are spaced apart in a fcommon plane, an annular heater `circumferentially enclosing said matrix in heat transfer 'relation thereto when said segments are in said curing position, a plurality of links respectively ipivotally connected at their ends with said heater and with said respective segments, said links extending radially of the axis fof said matrix when said segments are in said closed position enclosed by said heater, .and "means for moving said heater and :said matrix axially relative to each -other lwhereby the .ends of the links connected with said segments 4will .be .causedto swing radially outwardly of said Taxis l.for moving said segments -"to said open position, said means for moving "said heater and :said :matrix axially relative to each other including a ilui'd actuated piston `rod coaxial with the axis 'of said matrix connected with said 'platform for axially moving said vplatform `and -matrix away from said heater, and means for holding said heater stationary during said movement o ysaid platform.

10. A Vretreading mold vcomprising lan annular matrix divided :into a plurality of segments, a' tread plate removably supported in each 4of said segments for movement into 4and out yof each segment in a direction circumerentia'lly Aof said matrix, means supporting said segments for movement radially of the axis o'f said matrix from a curing position with said `treadl plates in end to end adjoining relation to open position with said 'segments and said tread plates spaced apart whereby said tread plates maybe removed lfrom said segments -or 'replacement when said segments are in said open position', an annular heater ycircumferentially enclosing said segments in heat transfer relation thereto when said Ysegments yand tread plates are insaid curing position, said heater being a hollow mem; ber providing an annular chamber for steam, means `for 'relatively moving said heater and said matrix to spaced relation indifferent planes upon movement Aof said segments to said open position, said `means vincluding vlinks pivotally connecting said segments with -said heater.

HAROLD .L BAKER. RAYMOND D. VAN TASSELL.

REFERENCES CITED 'The following references .are 'of record in the Ville of this patent:

UNITED 'STATES PATENTS Number Name Date 1,642,947 Fischer Sept. v20, 1927 1,679,788 Schroeder Aug. 7, 1928 1,801,335 Denmire Apr. 21, 1931 1,916,798 Hottel .July 4., 1933 2,023,002 Bosomworth Dec. 3., 1935 2,024,554 Vogt Dec. 17, 1935 2,186,882 Rawls et al Jan. 9, 1940 2,305,412* Frolich et al Dec. y15, -1942 2,330,762 Tooker Sept. 28, 1943 2,345,172 Bacon .Mar. 28, 1944 2,372,644 Bacon Apr. .3, 1945 FOREIGN P'A'IENTS Number Country Date 113,854 Austria July AT25, 1929 

